Publication at Faculty of Mathematics and Physics |
2011
Abstract
Hydrogen pressure of 0.5-140 bar has been applied to synthesize hydrides of UCoGe. Besides an alpha hydride crystallizing in the structure type of the parent compound, which loses the weak ferromagnetism found in pure UCoGe, two distinctly different beta hydrides were identified.
The almost pure beta hydride (UCoGeH(1.7)) is a ferromagnet below T(C) = 50 K. The highest H(2) pressures (} 130 bar) produce admixture of another hydride called beta'' hydride, with less H/f.u. and T(C) = 8 K, obtained presumably as a decay product of a full hydride UCoGeH(2.0) unstable at ambient conditions.
The value of the Sommerfeld coefficient of electronic specific heat gamma increases over 100 mJ mol(-1) K(-2) for the magnetic hydrides.